Add command to find base commit for creating a fixup

pkg/commands/git_commands/blame.go

@@ -0,0 +1,33 @@
+package git_commands
+
+import (
+	"fmt"
+)
+
+type BlameCommands struct {
+	*GitCommon
+}
+
+func NewBlameCommands(gitCommon *GitCommon) *BlameCommands {
+	return &BlameCommands{
+		GitCommon: gitCommon,
+	}
+}
+
+// Blame a range of lines. For each line, output the hash of the commit where
+// the line last changed, then a space, then a description of the commit (author
+// and date), another space, and then the line. For example:
+//
+//	ac90ebac688fe8bc2ffd922157a9d2c54681d2aa (Stefan Haller 2023-08-01 14:54:56 +0200 11) func NewBlameCommands(gitCommon *GitCommon) *BlameCommands {
+//	ac90ebac688fe8bc2ffd922157a9d2c54681d2aa (Stefan Haller 2023-08-01 14:54:56 +0200 12) 	return &BlameCommands{
+//	ac90ebac688fe8bc2ffd922157a9d2c54681d2aa (Stefan Haller 2023-08-01 14:54:56 +0200 13) 		GitCommon: gitCommon,
+func (self *BlameCommands) BlameLineRange(filename string, commit string, firstLine int, numLines int) (string, error) {
+	cmdArgs := NewGitCmd("blame").
+		Arg("-l").
+		Arg(fmt.Sprintf("-L%d,+%d", firstLine, numLines)).
+		Arg(commit).
+		Arg("--").
+		Arg(filename)
+
+	return self.cmd.New(cmdArgs.ToArgv()).RunWithOutput()
+}

pkg/commands/git_commands/commit.go

@@ -198,6 +198,20 @@ func (self *CommitCommands) GetCommitMessagesFirstLine(shas []string) (string, e
 	return self.cmd.New(cmdArgs).DontLog().RunWithOutput()
 }
 
+// Example output:
+//
+//	cd50c79ae Preserve the commit message correctly even if the description has blank lines
+//	3ebba5f32 Add test demonstrating a bug with preserving the commit message
+//	9a423c388 Remove unused function
+func (self *CommitCommands) GetShasAndCommitMessagesFirstLine(shas []string) (string, error) {
+	cmdArgs := NewGitCmd("show").
+		Arg("--no-patch", "--pretty=format:%h %s").
+		Arg(shas...).
+		ToArgv()
+
+	return self.cmd.New(cmdArgs).DontLog().RunWithOutput()
+}
+
 func (self *CommitCommands) GetCommitsOneline(shas []string) (string, error) {
 	cmdArgs := NewGitCmd("show").
 		Arg("--no-patch", "--oneline").

pkg/commands/git_commands/diff.go

@@ -78,3 +78,11 @@ func (self *DiffCommands) OpenDiffToolCmdObj(opts DiffToolCmdOptions) oscommands
 		Arg("--", opts.Filepath).
 		ToArgv())
 }
+
+func (self *DiffCommands) DiffIndexCmdObj(diffArgs ...string) oscommands.ICmdObj {
+	return self.cmd.New(
+		NewGitCmd("diff-index").
+			Arg("--submodule", "--no-ext-diff", "--no-color", "--patch").
+			Arg(diffArgs...).ToArgv(),
+	)
+}